Means for lapping taper sided split rings



June 28, 1.949.

J. W. HOWLETT ET AL Filed Feb. 5, 1947 MEANS FOR LAPPIG TAER SIDED SPLIT RINGS f4 Il l Hol NVENTo 5 W Jaim, W owl@ June 23, 1949- J. HowLET'T Er AL y 2,474,358

MEANS FOR LAPPING TAPER SIDED SPLIT RINGS Filed Feb. 5, 1947 v v 2 Sheets-Sheet 2 J i l 1 4 Ill''l l 4/ H 49 4f s; i

l IN VEN TRS 5PZ/zur fUOZCOZZ' y MM Patented June 28, 1949 fFORiLABPING:TABERUSIDEDE f SBIiIT RINGS.

J ohn 'Williams 'Hti'wlett and Arthur al.'x Woolcott,j

Engl-indd ApplieatidmFebiuary In` Great Britain 1947, Serial No..'726,160 November 24,y 1941 Sectiml, lubliesLaw 690; :August 8,'11946;

November 24,v 1961` -f Patientu expires This invention.4 relates. to ...piston-rings, such as are commonly known, the kind of which atleastione sideliaceisnoti a plane at right-.anglestmthe axis oflthering,

This side face is usually in `th'efornroi a truncated cone, but instead i of being I Hatfit may, be. convex l or concave to a small extent;m

It is found in practice. thatwhereas. suchlrings, have certain advantages .in use. there .is a. tendeA ency for the ring.groovesinithefpistonto. wearat a rather high rate, due,l in.all.probability, tothe abrading action of the .sidefface-oa ringpnthe.- adjacent side race .oaf the groove.as..fthe.frin'g:expands and contracts in the groove...

It is our main object tQ-.preventthisrfrom,happening.

A further object is to `arrange for ,thefsaidjside face of the ring to be. honed orlapped .byrnech'ane-A ical means, and preferably the irregularityjn the,`

surface finish of the. sideace should not. exceed. fifteen micro-inches.,

A further objectis...to.- provide .a mechanical. means for .honing 1v or. .lapping a ,side.face...o..a piston-ring `as aforesaid,V luy-which .the .honing rorf. lapping block is .movedcircumferentiallyfrela. tively to the. ring,` I and also..oscillated.tofandfro` ina more or less radial,directiorrrwith:respectto.l the ring.

For a better understandingbf.. .these ^andother objects and advantages of the invention ,attention should be directedto the `following -descriptioninA Which reference.. is made `to the.. accompanying sheets of diagrammatic -drawingsflwherein-f- Figure 1 is a vertical section throughone form. of mechanical meansas aforesaid Figure 2 isa sectional .plan .view-takenronthe line II-II of Figure 1;.

Figure 3 is a fragmentary perspective vier/,and cross-section taken on... the line. of Figure 2;.

Figure 4 is afragmentary planviewofraportion. of the ring and base; and

Figure 5 is a 'part-sectional. elevation .oi another. form of mechanical means. as aforesad In the construction of Figiures .1 td,4 there isr a base built up of a'centralportion Il and la sur. rounding annular portion I2 Whichiare secured ,to one another inany convenientmannerJu Tlieupf. per surface ofv the central.portidn is.`offrusto. conical shape corresponding. to vtlfietapger. ,oi-Qa. taper-ring I3 which is. to. be treated,;the lring] 3 in this case having xa.corresponding.taper onlbothl sides. The l annular -.portion;| 2 lforms ,.a .backa ing` for 'the ringv4 Whenplaced*in .positionlon the. centralv portion, .engaginggthelperiphervi thereof y nulus l8,.the latter beingiormed as shown. byvFgures 3 and 4.' The ring is held :I4 secured* asby 4screws tothe annular portion: andlraving;Y

against movement by'means. of 'a .lug`

a, tongue I5 'projecting overl the "central portion u into the gap at the. ends. of the ring,as shown by:`

Figure 4.

The head of the machine com-prisesarotatable' portion IB which in this case, is shownas..beirig` fast with a driving shaft'll,Y and a statio'narygan- With'lugs I9 tto engage corresponding recesses 2I` formed in the rim of the annular base portion I2 when the head is moved into engagement with'the base'. On the underside of the rotatable. portion of .the head. of slides' 23224' each of which is of Tshape, as shown by,lig1;1r.e4 3,"

there are Aarranged two pairs being carried in aT-sectionslot .formed in the head. .y Each slide carries a bl0ck`26', for example, a honingstone, or, as will'lbe Weltunderstoodfif. preferred, the block 26 may be a cast-iron lapping blockto act on the surface,l .of the ringthrouglgr a suitable lapping medium...

The stationary portion I8 carries two superposed cam rings 21, 28 secured as by .means of screws 29. The ycontours of these are substantially.` similar but .angulairly staggeredfll One .pairyoi slides (the pair 23 inthis instance). lengagesthe top cam 27, and the other. pair otfslides .24'. engages. the bottom. cam 28. The. slides. are heldin-en-n gagement with the cams by means of aring' disposed Iloosely.,I round lthe, shaft-end ,i and .retained in position .by resting. uponledges 3 IT formed at the radially-inner endsof the slides.

Thus, when the shaft I1 is rotated Ithe slides travelling -round the .oamsuracesare ,oscillated radially `withrespect to .theheaotW The operative surfaces of the block. 2B .are paralleLtol the taper of the ring, .as are also the. slide's.-.23,l24. .The ar. rangement. is. suchit. ,will be.` observed, that..the operative .surface of .the .ring `canfbe `very accurately honed, the honing. fstonesof. the. slides 23 overlapping. in their .travel thepath of. travel of, the honing -stones .in .the .slides .2ILy Inpontfof. fact, we arrange for the regular-ity.in.thef.surface finish not to .exceed fteen .micro-inches Y.and preferably to be less..

For ringshaving a diierenttaper. oa .sideiace itwill be -obvious that 4a -di'erentbasercentre I l Willbe requiredfor the support. of. .theringand a .diierent head centre .I 6 in vorder. thatrthe. move-.. ment of the slides shall beindirections parallel to. the .adjacent side face of .the.ring..vf Alternatively, as-Will be .Well understood., the .slides,...may.;.*be mounted .in partswhich are adjiistableinthehead f or this purpose.

It will also be evident that the number of slides to be used or the number of cam rings can be varied as required. Furthermore, if preferred, the shaft Il may be held stationary and the base (and with it the cam ring) rotated.

In the construction shown by Figure 5 there is a stationary base 33 in which is journalled a rotatable base 34 carrying the piston-ring 35 which is to be treated. The rotatable base is formed with a stem portion 31 having Worm teeth 38 thereon engaged 'by a worm 39. Rotation of the Worm 39 therefore serves for rotating the rotatable base.

The head 4l is in this case stationary, being formed with eyes which slidably receive guiding rods 42 fast with the stationary base, but `ournalled in the head are four sleeves 44 in which are eccentrically mounted four pins 45. The upper ends of the pins are interconnected by a plate 46 whereby the pins are held against rotation, and at their lower ends are mounted honing stones or lapping blocks 4l. As shown in the figure, a block 41 may be mounted in a holder i8 which is dowelled at 49 to the associated pin 45 and is retained in position by a nut 5i. The upper ends of the sleeves carry gear wheels 52, all of which are in mesh with a central gear Wheel 53 fast on a driving shaft E55, the latter err-- tending through a clearance hole in the plate 6.

In consequence the rotation of the driving shaft will rotate the sleeves lill and thereby efect oscillation of the pins a5 in a more or less radial direction with respect to the ring 35, carrying the honing or lapping blocks across the surface of the ring While the latter` is being rotated by the rotatable base.

If desired, the sleeves Lid may be adjustably supported in the rotational portion of the head, their gear wheels 52 being connected with the driving gear wheel 53 through ldle gears whereby to allow of the adjustment of the pins f5.5 according to the size and shape of a ring to be treated.

In like manner it will be understood that in either of the constructions described, if it be desired to hone or lap a ring which is slightly convex or slightly concave, the slides 23, 2a in the rst example, and the pins i5 in the second example, must be mounted to provide the necessary movement.

It is desirable that the honing or lapping eX- erted by the head on the ring should not be less than 20, or more than 150, pounds per square inch.

What We Claim as our invention and desire to secure by Letters Patent of the United States is:

l. A mechanical means, for honing or lapping a side face of a taper-sided split piston ring, including a base adapted to support the ring, means fast with the 'base for engaging in the split of the ring for preventing relative rotation between said ring and said base, a head carrying a slide, the slide supporting a honing or lapping block in contact with the appropriate side face of the ring, means for effecting relative rotation of the head and base, and cam means coacting with the slide so as to oscillate the latter during such relative rotation, the slide and honing or lapping block being mounted so that the oscillatory movement of the said block will be parallel to the taper of the side face of the ring.

2. A mechanical means, for honing or lapping a side face of a taper-sided split piston ring, including a stationary base adapted to support the ring, means fast with the base for engaging in the split of the ring for preventing relative rotation between said ring and said base, a rotary head, an annular member rotatively carried by said head, interengaging teeth of said stationary base and annular member for preventing rotation of the latter, a slide carried by said head, the slide supporting a honing or lapping block in contact with the appropriate side face of the ring, means for eiecting relative rotation of the head and base, and cam means which are carried by said annular member and which coact with the slide so as to oscillate the latter during such relative rotation, the slide and honing or lapping block being mounted so that the oscillatory movement of the said block will conform to the shape of the side face of the ring.

3. A mechanical means, for honing or lapping a side face of a taper-sided split piston ring, including a base adapted to support the ring, means fast with the base for engaging in the split of the ring for preventing relative rotation between said ring and said base, a head carrying a slide, the slide supporting a honing or lapping block in contact with the appropriate side face of the ring, means for effecting relative rotation of the head and base, annular cam means coacting with the radially outer end of the slide, and means for biassing said slide for its said outer end to maintain contact with said annular cam means so that said slide is oscillated during such relative ro tation, the slid and honing or lapping block being mounted so that the oscillatory movement of the said block will conform to the shape of the side face of the ring.

4. A mechanical means, for honing or lapping a side face of a taper-sided split piston ring, including a base adapted to support the ring, fast with the base for engaging in the split of the ring for preventing relative rotation between said ring and said base, a head carrying a plurality of radially arranged slides,eachsaid slide supporting a honing or lapping block in contact with the appropriate side face of the ring, means for efecting relative rotation of the head and base, a plurality of annular cam means with wavy contours respectively engaged by the outer ends of different slides, and means for biassing said slides for their said outer ends to maintain contact with said annular cam means so that said slides are oscillated during said relative rotation, the slides and honing or lapping blocks being mounted so that the oscillatory movement of the said blocks will Conform to the shape of the side face of the ring.

5. A mechanical means, according to claim l, of which the means for .biassing the slides is a loosely supported ring of which the outer periphery bears on the inner ends of said slides.

6. A mechanical means, for honing or lapping a side face of a taper-sided split piston ring, including a base adapted to support the ring, means fast with the base for engaging in the split of the ring for preventing relative rotation between said ring and said base, a head carrying a plurality of slides arranged radially in aligned pairs, each said slide supporting a honing or lapping block in contact with the appropriate side face of the ring, means for effecting relative rotation of the head and base, a plurality of superposed annular cam means with wavy contours respectively engaged by the outer ends of a said pair of slides, the cam means being orientated to stagger their respective wavy contours, .and means for -biassing said slides for 4theirsaid outer ends to maintain contact with the coacting annular cam means so 5 6 that the said slides are osoillated during said relative rotation, the slides and honing or lapping UNITED STATES PATENTS blocks being mounted so that the oscillatory Number Name Date movement of the said blocks will conform to the 1,546,525 Wasson July 21, 1925 shape of the side face of the ring. 5 2,168,753 Smith Aug. 8, 1939 JOHN WILLIAM HOWLETT. 2,315,859 Indge Apr. 6, 1943 ARTHUR J. WOOLCOTT. 2,372,341 Shanley Mar. 27, 1945 2,406,690 Indge Aug. 27, 1946 REFERENCES CITED The following references are of record in the 1 le of this patent: 

